The addition of the CD20-directed monoclonal antibody 90Y-Ibritumomab tiuxetan to a reduced-intensity fludarabine-based conditioning regimen followed by allogeneic transplantation appeared safe and effective in patients with chemosensitive advanced high-risk B-cell lymphoma, according to results of a multicenter phase 2 trial.
Patients with advanced B-cell non-Hodgkin’s lymphoma who are refractory to initial chemotherapy or relapse after autologous stem cell transplant have a poor prognosis. Transplantation after a reduced-intensity conditioning regimen may be an effective therapeutic option, yet the high incidence for relapse remains a formidable challenge, according to background information provided by researchers.
Krimo Bouabdallah, MD, of the department of hematology and cellular therapy at Haut-Leveque University Hospital in France, and colleagues evaluated the safety and efficacy of 90y-ibritumomab tiuxetan (Zevalin, Spectrum Pharmaceuticals) in combination with a reduced-intensity conditioning regimen of fludarabine (Fludara, Bayer HealthCare), busulfan and antithymocyte globulin followed by allogeneic transplant.
The analysis included 31 patients treated at five institutions between February 2008 and October 2010. Thirty patients in complete or partial response were evaluable for non-relapse mortality at day 100 post-transplant. These patients had failed a median of three previous chemotherapy regimens (range, 2-4), and 29 had undergone prior autologous transplant.
Median follow-up was 32 months.
At 2 years, EFS and OS rates were both 80% (95% CI, 60.8-90.5).
Cumulative incidence of non-relapse mortality was 3.3% (95% CI, 0.2-14.9) at 100 days post-transplant and 13.3% (95% CI, 5.4-33.2) at 2 years. The 2-year cumulative incidence of relapse was 6.7% (95% CI, 1.7-25.4).
Cumulative incidence of grade II to grade IV graft-versus-host disease (GVHD) was 27%, and cumulative incidence of extensive chronic GVHD was 14%.